| 摘要 |
<p>A differential pressure sensing valve has an axially shiftable spool including axially-spaced spool areas on which a pair of pressure sources connectable with such valve act in a predetermined direction with spool shifting force. Biasing means normally biases such spool with spool shifting force in a direction opposite to the predetermined direction. The opposite spool shifting forces are substantially balanced over the normal operating range of the pressure sources for maintaining such spool in an operating position for normal flow of fluid through the valve. Such opposite spool shifting forces are substantially unbalanced for shifting such spool out of such operating position when the pressure sources substantially deviate from their normal operating range.</p> |
